18 Oct 2012

Kermadec Whales and Dolphins

From Our Changing World, 9:46 pm on 18 October 2012


Rochelle Constnatine and Clinton Duffy preparing to collect a biopsy sample from a dolphin, and the Pew science team on board HMNZS Canterbury

Rochelle Constantine and Clinton Duffy aboard a navy inflatable boat getting ready to collect biopsy samples using a biopsy rifle, and the Pew science team, including Rebecca Priestley (second to left). (images: Bruce Foster)

Two weeks ago science write Rebecca Priestley reported on the mysterious floating pumice caused by an underwater eruption along the Kermadec Arc. She was on board HMNZS Canterbury en route to Raoul Island in the Kermadecs, along with Department of Conservation staff, a group of students on a Sir Peter Blake Expedition and a science team sent by Pew Environment Group, which included Rochelle Constantine from the School of Biological Sciences at the University of Auckland. Rochelle is a marine mammal expert, and she is trying to collect biopsy samples from bottlenose dolphins and humpback whales in the waters around the Kermadecs to try and solve the mystery of exactly which species the dolphins belong to, and which population the humpback whales belong to.

Rebecca Priestley goes ashore on Raoul Island to talk with Department of Conservation staff about their annual whale survey, and follows Rochelle during the expedition as she attempts to collect biopsy samples, finally succeeding in getting a single dolphin sample.

Rochelle has now analysed that sample and here is her initial report: “Our sample from our trip was from a female bottlenose dolphin. After some initial uncertainty, we now know that the bottlenose dolphins at Raoul Island are the same type as found around coastal NZ - Tursiops truncatus. There were some thoughts that they might be the smaller Indo-Pacific form that is found in warmer water regions like Australia, New Caledonia and the Solomon Islands - but we can now rule that out. Initial examination of the genetics show some shared haplotypes (maternally inherited DNA) with dolphins found in Northland, but to say anything conclusive we will need more samples from this population. I am excited about the possibility of chipping away at this question of how the Raoul Island dolphins are linked to mainland New Zealand - the fact they are the same species is a very interesting beginning and will keep working on this population.”

You can find stories from last year’s Kermadec series here, and a previous Our Changing World interview with Rochelle Constantine, in which she talks about the results of the joint Antarctic whale research consortium, and speculates on the humpback whales in the Kermadecs.